We did a clinical trial of succimer to treat moderately lead poisoned children. We found no effect of succimer treatment on cognition or behavior, reported previously. Recently, we have arranged with CDC to analyze blood samples collected in this project for methyl mercury, inorganic mercury, and cadmium, which allowed a randomized trial of succimer for chelation of these compounds without enrolling any new subjects or collecting any specimens. Succimer does not appear to be an efficacious chelating agent for mercury or cadmium. Neither mercury nor cadmium, measured at age 2 years, is associated with cognitive or behavioral test scores, and cadmium is not associated with blood pressure. We recently received results of analysis of the blood samples from the oldest children, age 7 years, for mercury, and are examining them for associations with IQ and behavioral test scores